Coffee-grinder.



W. F. STIMPSON.

COFFEE GBINDEB.

APPLIOATION Hmm Nov.19. 190s.

1,086,868. y Patented Feb.1o,191L

2 SHEETS-SHEET 1.

w. F. sT'IMPsoN.

COFFEE GRINDBR.

APPLIoA'rIoN FILED 110mm, 190s.

Patented Feb. 10QA 1914,

2 SHEETS-SHEET 2.

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Wfnesses Adam@ UNlTED sTATns rai-inn union.

WALTER F. STIIVIPSON, OF DETROIT, MICHIGAN, ASSIGNOB, TO STIMPSON SCALEAND MANUFACTURING COMPANY, F NGRTHVILLE, IVIICIG-AN, A .CORPOBAATIGN 0FMICHIGAN. y,

COFFEE-GRINDER.

1,086,868. Specification of Letters Patent. Patented Feb. 1e, 1era.

Application filed November 19,1908. Serial No. 483,416.

To all 1071 om it may concern Be it known that I, WALTER F. S'rrMrsoN, acitizen of the United States of America, residing at Detroit, in thecounty of Wayne and State of Michigan, have invented certain new anduseful Improvements in` Coffee-Grinders, of which the following is aspecication, reference being had therein to the accompanying drawings.

The invention relates to coffee grinders, and consists in variousfeatures of construction as hereinafter set forth.

In the drawings Figure l is an elevation of a hand-operated machine;Fig. 2 is a similar view of a machine that may be operated eithermanually or by a motor; Fig. 3 is a vertical section through themachinelongitudinally of the` grinder shaft; Fig. 4 is a section on line.7a-@Figa 3; and Fig. 5 is a sectional elevation ofthe ratchet crank.

In the construction ofcoffee grinders it is desirable to so proportionthe parts, and particularly the size of the grinders, as to obtain aslarge a capacity as possible without exceeding the power which may beeasily developed by hand? InO other words, the machine must operate;easily and at the same time grind as yquickly as possible. In

practical use, the coffee is ground to various degrees of iineness andfor the finer grades, and particularly the pulverized coffee, more poweris required with a given size of grinder than for the coarser grades. Itis therefore apparent that if the grinders are proportioned for easyoperation and the maximum capacity, where grinding coarse they will bedifficult to operate when grinding fine.; or, if proportioned for easy oeration in fine in capacity for coarse grinding.` This difli- `culty Ihave avoided by providing two sets of grinders of dierent size andcapacity, and which are operated by the same mechanism. One :set ofgrinders is proportioned for `maxi-mum capacity within the power limitsfor vthe tine grades, and the other is cm'respondingly proportioned forthe 4coarscr grades.

In detail, A is a hollow pedestal within which is arranged a verticalshaft B having mounted on its lower end a fly Wheel C.

D is a horizontal shaft which is connected with the veitical shaftthrough the ybevel gear wheels F and F. Upon opposite sides of thesegear wheels are arranged pairs of grinding they will be lacking grindersG and G respectively for the fine I disk H.

operates to grinder from the stationary L is a member sleeved upon theshaft G f and provided with a conical bearing L which engages a. ballbearing J in the grinder J. The outer face of this member L is cammedand has a thrust bearing upon the stationary frame, the arrangementbeing such that by relatively adjusting said member L it will be movedlongitudinally of the shaft D and will adjust the member J toward orfrom the coperating member H. Beyond t-he member L a roller bearing M isarranged to form a journal for the shaft D, and this bearing is placedin a pocket in the casing N, which surrounds the grinders. Thus theshaft B is journaled atits opposite ends and the bearings aresufficiently removed from the grinders to permit of lubrication withoutdanger of the mixingof the lubricant with the coffee.

For holding the unground coffee, a receptacle O is arranged above theframe I, and a rotary gate P is arranged to control the discharge fromthis receptacle and to direct it alternatively to the fine and coarsegrinders. The discharge passage to these grinders is formed within theframe I through a central recess within the grinders H and J from whichthe coffee is fed outward between the grinding faces.

.Upon one end of the shaft D is arranged an operating Acrank Q, whichhas a ratchet engagement with the shaft so as to permit the independentrotation of the Alatter through the momentum of the Hy wheel, or, wherea motor R is used, it is placed in the base of the pedestal and has a.detachable drive connection with the fly wheel C, preferably'a pinionon the motor shaft engaging A K is placed between the frame I and gearteeth on the under side of the Hy wheel and thrown into or out of meshtherewith by raising or lowering the motor frame, as by the adjustingscrew R.

With the construction as thus far described, in operation the machinemay be driven either by the crank Q or by the motor R. Where the formeris used, the motor is lowered to disengage the pinion from the gearteeth on the fly wheel so as to permit the latter to rotate freely.Motion is then imparted to the mechanism by the operation of the crankand the movement is communicated from the shaft D to the shaft B and flywheel C. The gear F is of larger diameter than the pinion E, andconsequently the shaft B will be driven at a higher angular speed sothat a greater momentum is acquired by the ily wheel than if arrangeddirectly upon the shaft B. This permits of making the wheel small enoughto go within the base of .the pedestal and at the same time providessufficient factor of inertia to steady the operation of the machine. IfVthe coffee is to be ground line, the gate l? is turned to deflect thematerial into the grinder G, while for the coarser grinding the gate isturned opposite to deflect the coffee into the grinder G. Both of thesegrinders are capable of being adjusted by a rotation of their respectivebearing members Ii, and this adjustment is effected by a handle I?,which engages a notched bearing N in the easing N.

It frequently happens that the unground coffee contains foreignsubstance, such as pieces of metal, which Would break the teeth of thegrinder if dropped thereon when the machine is in operation. Toavoid-this, I have placed a friction coupling between the ear F on the shaft D, this being so adjusted as to yield under an abnormal stress andpermit the grinders to remainv stationary during the continued rotationof the fly Wheel. This friction, yas sho-wn, consists of a pair ofclamping plates S S secured to the hub upon the shaft D and engaging theweb of the wheel F with a washer S2 of fiber or other suitable materialin between. The plates may be clamped with just suf ficient tension todrive the grinders under normal load, and thus the introduction of anyforeign substance of a harder nature than coffee will arrest movement ofthe grinders and gear while the fly wheel continues to rotate..

lVhere a nail or other foreign substance arrests the grinders, as abovedescribed, it is necessary to separate the disks a sufficient distanceto permit the dislodgment of the same. This is accomplished by formingthe cam face on the member L with pockets T which engage bearing lugs Ton the thrust member T2. The pockets are of suiiicient depth to permitof withdrawing the disk J a greater distance from the disk same,

1 ,ceases I-I than is necessary for the coarsest adjustment of thegrinders, and thus at any time said grinders may be separated for thedislodgment of any clogging substance.

The member T2 is held from rotation by the engagement with lugs T3 uponthe casing N and a rotary adjustable oammed plate U is arranged betweenthe plate T2 and the casing. This plate U is adjustable for the purposewear in the grinders,V so that the adjustment of the member L in any oneposition will always produce the saine degree of fineness in thegrinding.

What I claim as my invention is:

1. In a coffee mill, the combination of a drive shaft, of a coarsegrinder driven from said shaft, a pulverizing grinder also driven` fromsaid shaft, and of lesser capacity than the coarse grinder tosubstantially equalize the power required to drive said shaft in thesame relative positions of adjustment of said grinders, said grindersbeing adapted for independent use, and means for independently feedingmaterial to said grinders.

2. In a coffee grinder, the combination of a shaft, of a hand crank forrotating the a coarse grinder mounted on and driven by said shaft, apulverizing grinder also mounted on and driven by said shaft and oflesser, capacity than the coarse grind-er to substantially equalize thepower required to drive the shaft in the same relative positions ofladjustment of said Grinders, said grinders being adapted for independentuse, and means for independently feeding material to the grinders.

In a coifee mill, the combination with a shaft, of a hand crank forrotating the same, mounted on and driven by' said shaft and adapted forindependent use, each of said grinders comprising complementary disks,the disks of the pulverizing grinder having the grinding surface thereofof lesser size than the grinding surfaces ofthe disk of the coarsegrinder whereby said pulverizing grinder is of lesser capacity than thecoarse grinder, to substantially equalize the power required to drivesaid shaft in the same relative positions of adjustment of saidgrinders, and means for independently feeding material to said grinders.

In testimony whereof I affix my signature in presence of two witnesses.A

WALTER F. STIMPSON. litnesses NELLIF. KrNSELLA, JAMES P. BARRY.

of compensation for any aV coarse, and a pulverizing grinder"

